In home caregiver assistance help, what should she pay me?

This is difficult, but is there some way to let her children know that you cannot assume this responsibility on your own. Let them know they will be blessed for helping out in any way needed. Otherwise, perhaps find an advocate who can speak to them. You should not be carrying all of the weight. Bless you.

Instead, of paying you, hire a PSW to do the job.
Your 'job' should be being a sister (sounds like you are the model kind)
There is no price that can be put on your happiness and independence.. besides, she needs you healthy and happy. What good would money do you if you cannot enjoy it anyway?
If there is a way to look after your sister and yourself at the same time, go that route even if you split it between you and a psw ...but in taking care of your sister you have to also take care of yourself.
She is so lucky to have you for a sister and I am guessing she knows it.

You may want to check with an elder care attorney for an actual contract. When my mom and I went to one for updating her will and doing the POA, we talked about this. I remember her saying something about $15/hr, but then we have gone through care.com and note that caregivers in our area are more around the $20-25/hr. rate.

We never went through with this at least not yet. I didn't want to deal with the business side of that, with reporting to IRS and taxes taken out, etc.

Hopefully, others who are doing this will give you better info. :)

Peggy, welcome to the forum!

You should not be "giving up your happiness" for your sister. Neither do her children have any "obigation" to help. Let's just be clear about that.

Is your sister paying you room and board, or are you splitting living expenses, like roommates?

If your sister requires a lot of caregiving, she should be hiring help to come in. If she is low income, she should apply for Community Medicaid to assist.

Contact your local Area Agency on Aging as a starting point. They will do a "needs assessment" and advise on her level of need and how to go about securing help. She would probably also benefit from 'case management' services.

https://www.officeonaging.ocgov.com/services/contracted-providers